BLOODY BIRTHDAY

On June 9, 1970, at a hospital in Southern California, three women give birth at the same time during a solar eclipse. Two boys and a girl are born - Curtis Taylor, Debbie Brody, and Steven Seton.

Ten years later, on June 1, 1980, Annie Smith and Duke Benson, a young couple are murdered in a cemetery by unseen assailants. The next day, the town sheriff and Debbie's father, James Brody, goes to the local primary school, where Debbie, Curtis and Steven are friends and classmates. James shows the class a jump rope handle that was found at the scene of yesterday's crime, but fails to obtain any new information about the murders and leaves. Later, after school, Debbie is playing in the backyard with Curtis and Steven. After Debbie shows James that the handle of her jump rope is missing, she gets Steven to beat him to death with a baseball bat, and the children frame the death as an accidental fall. Debbie notices that their classmate Timmy Russell has witnessed the murder.

After Sheriff Brody's funeral, Curtis and Steve lure Timmy to a junkyard and lock him inside an old refrigerator. Timmy manages to escape and tries to tell his older sister Joyce about the incident, but she doesn't believe him. A few days later, Curtis murders schoolteacher Mrs. Viola Davis. The children also attempt to kill Timmy and Joyce, but fail. That night, Joyce talks with Timmy about horoscopes; she tells him that—because a solar eclipse that occurred during the births of the three children blocked Saturn, the planet controlling the way a person treats other people—something is missing from their personalities. Meanwhile, Curtis murders two teens having sex in a van.

At the children's birthday party on June 9, Curtis tricks Joyce into believing that he poisoned the cake to make her look crazy to everyone. That evening, Debbie's older sister Beverly discovers a scrapbook owned by Debbie, which contains photos and news articles about the murders she and her friends have committed. She confronts Debbie over it, but Debbie lies and says the scrapbook belongs to Curtis. That night, Debbie murders Beverly and gets Curtis and Steven to help her move the body away from the house in order to avert suspicion.

After Beverly's funeral, Curtis, Steven, and Debbie attempt to murder Timmy again before Joyce intervenes. Debbie once again blames Curtis and Steven to make herself look innocent. Joyce threatens to call the police, but Curtis says they will dismiss her as crazy due to the incident at the birthday party, so an infuriated Joyce lets them go.

The next day, Debbie asks Joyce to babysit her and Joyce agrees, unaware that it is a trap. After Joyce and Timmy arrive at Debbie's house, she lets in Curtis and Steven through the back door. Curtis and Steven try to kill Joyce and Timmy. However, they successfully subdue the two boys and are able to call the police, who arrest Curtis and Steven the next morning as Debbie flees.

Some time later, Debbie and Mrs. Brody have fled to a new town and are staying at a motel, with Debbie now going by the name "Beth". Debbie, who had been playing with a truck jack, promises to be a good girl from now on. They leave together, as the camera pans to reveal a dead mechanic under a truck.

Curtis and Steven are subdued and arrested after a failed attempt to kill Joyce and Timmy; Debbie flees with her mother to a new town.

The film's climax sees the murderous children's reign of terror interrupted, but not entirely ended. While two of the trio face justice, Debbie escapes, implying that the threat may continue elsewhere. The ending underlines the chilling notion that evil can remain undetected and that outward innocence can mask deadly intent.